• Journal of Korea Multimedia Society
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• v.15 no.6
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• pp.731-736
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• 2012

Latest digital cinema is getting more interest on recent days. The combination of visually immersive 3D movie with chair movements and other physical effects has added more enjoyment. The movement of the chair is controlled manually in these digital cinemas. By the analysis of the digital cinema's video sequences, movement of the chair can be controlled automatically. In the proposed method first of all the motion of focused object and the background is identified and then the motion vector information is extracted by using the 9-search range. The motion vector is determined only for the movement of background while the object is stationary. The extracted Motion information from the digital cinemas is used for the movement control of the chair. The experimental results show that the proposed method outperforms the existing methods in terms of accuracy.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.7
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• pp.662-668
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• 2013

In this paper, possibility of controlling motion of a floating structure using a tuned liquid damper (TLD) is numerically investigated. A TLD is a tank partially filled with liquid. Sloshing motion of liquid inside a tank is known to suppress movement of the tank subject to external excitations at specific frequency. The effects of sloshing phenomena inside a rectangular floating body on its surge motion are investigated by varying external excitation frequency. First, a grid-refinement study is carried out to ensure validity of grid independent numerical solutions using present numerical techniques. Then, surge motion of the floating body subjected to external wave is simulated for five different excitation frequencies of which the center frequency equals to the natural frequency of internal liquid sloshing. The normalized amplitudes of surge motion of the target floating body are compared according to the excitation frequency, for the cases with and without water inside the floating body. It is shown that the motion of the floating body can be minimized by matching the sloshing natural frequency to the excitation frequency.

• Physical Therapy Rehabilitation Science
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• v.10 no.3
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• pp.257-262
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• 2021

Objective: Patients with stroke generally diminished ankle range of motion, which decreases balance and walking ability. This study aimed to determine the effect of ankle self-mobilization with movement (s-MWM) on ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in patients with chronic stroke. Design: Randomized controlled trial design Methods: Twenty-four post-stroke patients participated in this study. The participants were randomized into the control (n = 12) and self-MWM groups (n = 12). Both groups attended standard rehabilitation therapy for 30 minutes per session. In addition, self-MWM group was performed 3 times per week for 8 weeks. All participants have measured ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in before and after the intervention. Results: After 8 weeks of training, self-MWM group showed greater improvement in ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index than in the control group (p<0.05). Further, self-MWM group had significantly improvement in all dependent variables compared to the pre-test (p<0.05). Conclusions: Our investigation demonstrates that self-MWM is beneficial for improving functional ability. Also, self-MWM was superior to control with respect to improving ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.25 no.1
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• pp.9-19
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• 2019

Background: This study was planned to assess and compare the effectiveness of cervical region stabilization exercise and strengthening exercise on pain and range of motion in patient with chronic neck pain. Methods: Fifty-one patient with chronic neck pain were randomly allocated into strengthening and stabilization exercise (SSE) group (n=27) and Strengthening exercise (SE) group (n=24). The program was carried for 12 sessions, 3 days/week in 4weeks. Pain intensity with visual analog scale (VAS), cervical range of motion, deep cervical flexor strengthening were evaluated before and after the intervention. Results: After the program, pain intensity decreased in group SE and SSE were found (p<.05). Range of motion and deep cervical muscle strength increased in group SE and SSE were found(p<.05). The intergroup comparison showed that significant difference in range of motion and deep cervical muscle strength (p<.05). Conclusions: The study suggest that both SSE program and SE program might be a useful treatment for patients with chronic neck pain. However SSE program might be superior in improving cervical range of motion and deep cervical flexor strength compare to SE program.

• The Journal of Korean Physical Therapy
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• v.19 no.4
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• pp.43-51
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• 2007

Purpose: The purpose of this study was to determine the effects on improvement of the range of motion in the TM joint. Methods: 26 subjects who have TM joint limitation were divided to passive movement group(n=13, $21.3{\pm}2.95$ years) and active movement group(n=13, $20.62{\pm}1.39$ years). All of the subjects were treated 5 to 10 minutes per one time, five times once a week for 4 weeks by the physical therapist. The open bite and cross bite were investigated at before, during(2 wks) and treatment(4 wks). Results: In order to assure the statistical significance of the result, a Repeated measures ANOVA were applied at the 0.05 level of the significance. There was a significant difference in terms of the rates of open bite mean change in within-open bite effects among pre-test, post-test 2weeks and post-test 4weeks in each group(P=0.029). There was no significant difference in the rates of mean change in between-open bite effects(P=0.441) but interactions between two types of effects(P=0.025) were statistical significance among pre-test, post-test 2 weeks and post-test 4 weeks in each group. There was no significant difference in the rates of mean change in within-close bite effects(P=0.112), between-cross bite(P=0.179) and interactions between the two types of effects(P=0.098) among pre-test, post-test 2 weeks and post-test 4 weeks in each group. Conclusion: The results of this study showed that passive movement and active movement were effect on increase of TM joint ROM about open bite and cross bite.

• Earthquakes and Structures
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• v.16 no.5
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• pp.563-573
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• 2019

When generating spectrum-compatible artificial ground motion in engineering practices, the effect of the variation in fitting parameters on the distribution of the peak ground displacement (PGD) has not yet drawn enough attention. In this study, a method for simulating ground motion matching for multiple targets is developed. In this method, a frequency-dependent amplitude envelope function with statistical parameters is introduced to simulate the nonstationarity of the frequency in earthquake ground motion. Then, several groups of time-history acceleration with different temporal and spectral nonstationarities were generated to analyze the effect of nonstationary parameter variations on the distribution of PGD. The following conclusions are drawn from the results: (1) In the simulation of spectrum-compatible artificial ground motion, if the acceleration time-history is generated with random initial phases, the corresponding PGD distribution is quite discrete and an uncertain number of PGD values lower than the limit value are observed. Nevertheless, the mean values of PGD always meet the requirement in every group. (2) If the nonstationary frequencies of the ground motion are taken into account when fitting the target spectrum, the corresponding PGD values will increase. A correlation analysis shows that the change in the mean and the dispersion values, from before the frequencies are controlled to after, correlates with the modal parameters of the predominant frequencies. (3) Extending the maximum period of the target spectrum will increase the corresponding PGD value and, simultaneously, decrease the PGD dispersion. Finally, in order to control the PGD effectively, the ground motion simulation method suggested in this study was revised to target a specified PGD. This novel method can generate ground motion that satisfies not only the required precision of the target spectrum, peak ground acceleration (PGA), and nonstationarity characteristics of the ground motion but also meets the required limit of the PGD, improving engineering practices.

• Steel and Composite Structures
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• v.24 no.2
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• pp.141-149
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• 2017

In this study, vibration analysis of fluid conveying microbeams under non-ideal boundary conditions (BCs) is performed. The objective of the present paper is to describe the effects of non-ideal BCs on linear vibrations of fluid conveying microbeams. Non-ideal BCs are modeled as a linear combination of ideal clamped and ideal simply supported boundary conditions by using the weighting factor (k). Non-ideal clamped and non-ideal simply supported beams are both considered to show the effects of BCs. Equations of motion of the beam under the effect of moving fluid are obtained by using Hamilton principle. Method of multiple scales which is one of the perturbation techniques is applied to the governing linear equation of motion. Approximate solutions of the linear equation are obtained and the effects of system parameters and non-ideal BCs on natural frequencies are presented. Results indicate that, natural frequencies of fluid conveying microbeam changed significantly by varying the weighting factor k. This change is more remarkable for clamped microbeams rather than simply supported ones.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.4
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• pp.129-134
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• 2005

A numerical analysis was performed on magnetic field effects of silicon melt motion in Czochralski crystal puller. The turbulent modeling was used to simulate the transport phenomena in 18' single crystal growing process. For small crucible angular velocity, the natural convection is dominant. As the crucible angular velocity is increased, the forced convection is increased and the distribution of temperature profiles is broadened. The cusp magnetic field reduces effectively the natural and forced convection near the crucible and the temperature profiles of the silicon fluids is similar in the case of conduction.

• Wind and Structures
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• v.27 no.6
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• pp.431-438
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• 2018

This paper presents a free vibration analysis of size-dependent functionally graded (FG) nanobeams with all surface effects considerations on the basis of modified couple stress theory. The material properties of FG nanobeam are assumed to vary according to power law distribution. Based on the Euler-Bernoulli beam theory, the modeled nanobeam and its equations of motion are derived using Hamilton's principle. An analytical method is used to discretize the model and the equation of motion. The model is validated by comparing the benchmark results with the obtained results. Results show that the vibration behavior of a nanobeam is significantly influenced by surface density, surface tension and surface elasticity. Also, it is shown that by increasing the beam size, influence of surface effect reduces to zero, and the natural frequency tends to its classical value.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.51-58
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• 2020

Many types of optical plastic films are essential in optoelectronics display unit fabrication and it is important to develop high precision laser cutting methods of optical films with extremely low level of film surface contamination by fume particles. This study investigates the effects of suction and blowing air motions with air flow misalignment in removing fume particles from laser cut line by employing random particle trajectory simulation and probabilistic particle generation model. The computational results show fume particle dispersion behaviors on optical film under suction and blowing air flow conditions. It is found that suction air flow motion is more advantageous to blowing air motion in reducing film surface contamination outside designated target margin from laser cut line. While air flow misalignment adversely affects particle dispersion in blowing air flows, its effects become much more complicated in suction air flows by showing different particle dispersion patterns around laser cut line. It is required to have more careful air flow alignment in fume particle removal under suction air flow conditions.